There are many machines which are operated by means of hydraulic oil in hydraulic circuitry. During the operating of the machine the temperature of the hydraulic oil can exceed 40.degree. C. The present invention relates to a method of, and apparatus for, reducing heat present in the hydraulic oil.
A known arrangement for removing heat from hydraulic oil is to bring the oil and water in heat exchange relationship in a heat exchanger using low water inlet and outlet temperature to compensate for the poor overall heat transfer efficiency. Heat from the cooling water is dissipated to atmosphere by way of a spray cooling tower or the like.
There are various disadvantages with this known arrangement, one of which is that, if the temperature of the oil is reduced too severely, its viscosity is increased and provision for pumping the oil has to be increased.